More about this trial

Acral melanoma is a type most commonly found on the palms of the hands or soles of the feet. Mucosal melanoma is a rare type of melanoma that starts in the moist tissue (mucosa) which lines the mouth, nose, food pipe, anus, vulva and vagina.

Doctors usually treat advanced melanoma with chemotherapy. But sometimes this doesn’t work very well. So they are looking at new ways to improve treatment. In this trial, they are looking at a new drug called PLX3397.

PLX3397 is a type of biological therapy. It is a cancer growth blocker. It stops signals that cancer cell use to divide and grow. We know from research that PLX3397 may help people whose melanoma cancer cells have the KIT gene change.

The aims of the trial are to

Find out how well PLX3397 works for people with advanced acral or mucosal melanoma

Learn more about the side effects of PLX3397

Who can enter

The following bullet points list the entry conditions for this trial. If you are unsure about any of these speak with your doctor or the trial team. They will be able to advise you.

You may be able to join this trial if all of the following apply. You

Have acral melanoma or mucosal melanoma that has grown into surrounding tissues and can’t be removed with an operation or it has spread to another part of the body

Are willing to use reliable contraception during the trial and for 3 months afterwards if there is any chance you or your partner could become pregnant

Are at least 18 years old

You cannot join this trial if any of these apply. You

Have cancer that has spread to your brain unless it has been treated and you haven’t had any symptoms in the last 6 months (or in the last 3 months if you have 1 area of cancer spread to the brain). And you haven’t had steroids in the last month

Have had radiotherapy to more than a quarter of your bone marrow or you have had radiotherapy in the last month before you join the trial

Have a type of KIT mutation that is resistant to PLX3397

Have had treatment with a KIT inhibitor such as imatinib and dasatinib in the past

Can’t swallow tablets for any reason

Have a significant heart problem

Have problems with your liver

Have had major surgery in the last month or a skin sample (biopsy) taken in the 7 days before joining the trial

Have any other medical condition that the trial team think could affect you taking part

Are pregnant or breastfeeding

Trial design

This is a phase 2 trial. The trial team need 24 people to take part. Everyone taking part will have PLX3397.

Everybody who agrees to take part will have a tissue sample (biopsy) tested for the KIT gene change. The researchers may be able to test a sample that was taken when you had surgery for melanoma. Or they may ask to take a new sample. The test is done in a specialist laboratory. It takes about 2 to 3 weeks to get the results.

If the test results show that you don’t have the KIT gene change you won’t be able to take part in the trial. Your doctor will discuss other treatment options with you. If have the KIT gene change, you may be able to take part in the trial.

PLX3397 is a capsule. You have the capsules twice a day everyday with a glass of water. You should not eat for at least 1 hour before you take them and for 1 hour afterwards.

You have treatment for as long as it is helping you and the side effects aren’t too bad.

If you agree to take part in this trial, the researchers will ask to take extra blood samples. Where possible you have these at the same time as your routine blood tests. The researchers want to look for substances called biomarkers to find out why treatment might work for some people and not for others.

The researchers may also ask to take biopsies of your cancer at the beginning and during treatment. They will look for biomarkers and they may use it for other tests in the future. They are asking to take 3 samples in total. If you don’t want to give these samples for research, you don’t have to. You can still take part in the trial.

Hospital visits

You see the doctor to have some tests before taking part in the trial. These include

To begin with, you see the doctor 2 weeks after starting treatment and then

Every month in the first year of treatment

Every 2 months in the second year of treatment and then

Every 6 months

You have a CT or MRI scan every 3 months after you start treatment.
When you finish treatment, the trial team follow you up every 6 months. They may phone you or see you at a routine hospital appointment.

Side effects

PLX3397 is a new drug there may be some side effects we don’t know about yet. The trial team will monitor you during the time you have treatment and you will be given a phone number to call them if you are worried about anything.

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